Our principal accomplishments during the last year have been: 1) Neuro-vascular networks in pathological situations including obesity-related nerve disorders. We are engaged in a new project for studying what happens to the neuro-vascular networks in hyperglycemic animal models such as diet-induced obesity (DIO) mice and leptin receptor-deficient db/db mice, a severe obese and type 2 diabetic mouse model. We have developed a high-resolution whole-mount imaging method to analyze neuro-vascular branching in the entire ear skin of adult mice. This method enabled us to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels in the animal models of obesity and type 2 diabetes, with comprehensive quantification measurements (Yamazaki et al. 2018 Sci Rep). We are currently investigating the functional consequence of defective neuro-vascular branching using an intravital calcium imaging. 2) Contribution of non-vascular cells in organ-specific vascular development. How are the multiple vascular cell types (endothelial cells, pericytes, and VSMCs) assembled to form an organ-specific vascular network? Are non-vascular origins involved in the vascular development? Our studies demonstrated that there are tissue-localized myeloid progenitor-derived pericytes in the vasculature of the ectoderm-derived tissues such as skin and brain. Further genetic studies revealed that TGF- influences differentiation of myeloid progenitors into pericytes (Yamazaki et al. 2017 Cell Rep). Our studies clearly demonstrate that the developmental origins of pericytes are heterogeneous: some pericytes are derived from myeloid cells. To define the molecular definition of these pericyte subpopulations, we are carrying out a single cell RNA-seq analysis of freshly FACS-isolated PDGFR+ pericytes from embryonic skin, in combination with a total RNA-seq analysis of and myeloid cell-derived and mesenchymal cell-derived pericytes.